No, it is not simplest form. 12/40 = 3/10
12/40 is equivalent to 3/10 in its simplest form
40/96 = 5/12
3/10
3/40
3/10
Divide both by 4 so 12/40 = 3/10
40/49 is in its simplest form.
40/81 is in its simplest form.
171/40 is in its simplest form.
37/40 is in its simplest form.
40/403 is in its simplest form.